Carburetor



.lune 16,v 192s. 1,542,168

A. D. PATERSON ET AL QARBURETOR Filed Nov. 16, 1922 s sheets-sheet 1 "Hm- ,F v

ma: W

June 16, 1925. Y

' A. D. PATERSON ET AL CARBURETOR Filed Nov. 16, 1922 3 Sheets-Sheet 2 @nuenlrs t Jun 16, 192s. 1,542,168

, A. D`. PATERSON ET AL CARBURETOR Filed NOV. 16 1922 5 Sheets-Sheet 5 l f z T 'f M fz nl l nf Qnvenrs: @mdd Hamam,

Patented June 16, 1925.`

- UNITED STATESPATENT OFFICE Anonimi DONALD rArERsON AND MALCOLM ALLAN GRAY, or LONDON, ENGLAND;

-sAID GRAY AssreNoR ro sAID rA'rEnsoN.

cARBunE'rort. y y

Application nieu November 16,1922; semi No. cuisse.

To all e0/wm t may concern:

"Be it knownthat we, ARCHIE DONALD" PArniisoN and v MALCOLM ALLAN GRAY, residing at London, England, subjects 4of the King of GreatvBritain and Ireland, have invented certain new and useful Improvements in Carburetors, of which the follow-V ing is a specification.

This invention relates to carburetor-s and the primary object is to provide novel coniiensating means for obviating what is known as flat spot, which is a phenomenon oc` curring at periods in most carburetors pro-k videdwith means for supplying, in addition to the `mixture of fueland air supplied by the main nozzle, a. rich mixture forV start-` ing and slow ruiming purposes in advance of the throttle valve.

Such flat spot7 is due to the fact that on Opening the throttle to admit the niaini charge of mixture, the suction of the engine does not create sufficient vacuumto cause a charge of correct proportions to issue from the main nozzle; While it also dilutes the slow ruiming mixture .suddenly or to too great an extent. f i L Y A Now the present invention, broadly stated, consists in causing a charge of liquid fuel only, undiluted by any addition of air to issue at-low engine speeds into the induction pipe or mixing chamber or equiva# lent at a point adjacent the point of `issuance of the starting or slow running charge or mixture, buton the atmospheric side ofthev normal closed position of the throttle and as remote as possible from the `main nozzle. This charge` of undiluted fuel is drawn through a duct, the cross sectional area of which may be adjusted or calibrated to suit variousV requirements of the engine to which the carburetor is applied, and issues into the induction pipe under a `high suction, whereby there is `provided at that point and at slow engine speeds a charge which will, so to speak,` properly bridge the gap between `the usual starting charge of fuel mixed with air andthe main charge and thus overcome the objectionable fiat spot referred to.

The invention'furthercomprises the novel features of construction, arrangement and combinationof parts as hereinafter fully describedand specifically pointed out in the appended claim with reference to the ac-y companying drawings, in which, Fig. l is a diagram illustrating the principle of operation of the iinprovedcarburetor. Figs. 2 to ,a show one speciiicembodiment of the carburetor, FigQbeing a vertical section, Fig.

3 a plan view of Fig. 2. Fig. 4 a sectionA on line l--4 of Fig. 3; Figs. 5 to 7 show another specific embodiment, Fig. 5 being a vertical section; Fig. 6 being an elevation and Fig. 7 a half plan view, half section.

To first. `referto the diagram (Fig. l)

which will clearly demonstrate the principle of the invention, the carburetor shown is known as the vented nozzle type, that is to say, itis provided with a .well A normally filled with fuel to the level existing inthe float chamber B, and from which well leads a pipe C supplying the slow running device D which receives, by preference, a supply of heatedair asthrough `inlet E for forming" the starting mixture. Into said well also extends a duct,fpipe or the like F through whichthe auxiliary `charge of undiluted fuel is drawn to a point -F1 in the induction'pipe or mixing chamber G nearest the atmos-` pheric side of the throttle H at its'closed position and close to the point D1 at which the slow ruiming mixture issues. The pipe Fis provided with means shown at F2 by which its bore can be adjustedto vary-the quantity of liquid fuel passing therethrough for the purpose above stated. Y

The main nozzle I includes a calibrated the well A, the orifice being of less capacity than that of the main nozzle so that air as well vas. fuel is drawn from the nozzle at.

`orifice J normally submerged in the base of femptied in the normal operation of the carf bureto r. Y

The relatively large diameter of suol orifice J v and the advantage mentioned are permitted by the provision of an air tube VK into which said orifice discharges, this tube extendingto the main nozzle aperture o. umd? I1 and being provided in advance of said aperture with means for the supply of exterior air as at K1, other air holes Y2 being provided in the nozzle I. By this means the main charge of fuel, to which air has been previously admitted in the air tube at K1, issues from said tube to the Venturi tube L in the form of an emulsion prior to its admixture withthe main air supply admitted to said Venturi tubeat intake M.

Such double dilution of the main charge and its consequent economy of fuel are'rendered possible by the provision of the aforesaid auxiliary charge of undiluted fuel through F F1 at theperiod of slow engine speed, wliich'will thus provide a means of gradually regulatingthe charge at the varyingdegrees ofv-suction as thee-ngine picks upV speed since it provides in the. induction pipe GrY a rich mixturefor starting and slow running,.and immediately the throttle H is opened. the excess air coming through the n'iainairintake Mlmixes witlrthe undiluted fuelissuing fromits duct at F1 andbridges the gapbetwe'en Il` andF Thesaidstarting and slow running` charge is followed bya more attenuatedlmixture as vthe main nozzle comes into operation, the two former suppliesthrough F, F1 and D, D1 being automatically cut out ley-reason the wellA becomingA empty. There is thus produced a regulation ofy the charge preventing the forfmation of a, flat spot between the slow running device D and the main nozzle at l1.

To now. turirto the specific constructions of carburetors embodying4 the improvements operating on the principleoutlined above, Figs. 2 to 4 show aconstruction of vertical carburetor comprisingi a float chamber a with needle valve al and usual.' fuel filter assembly a?, thisiioat chamber communicating. through a calibrated: plug' Z) witlr the well c in. which is located' an airtube Z screwed into the openend of the welll Fromv thewell adjacent the air tube leads another ain tube Z1 having` airl apertures at cl2 and.v surroundedby an air-sleeve Z3 in the path of air from the mainv cold air intaked'. The air tube P terminates above in the nozzle e within the Venturi tube el which is shown as provided with the usual. adjusting plug e2 andlocated, as commonly practised, in induction. pipe c3 below the throttle Said lthrottle' is' provided. `with a regulator and. adjustment screw f1 and isy operated'A through lever. f2, the movement of which latter is controlled by a` stop l As shown more particularly in Fig.'4 4 there also extendsfrom thewell cv a pipe g1 leading to the slow-running device g, this pipe being adjustable as to height in said device and 4secured` in position ofv adjustment by means ofV a lock-nut g2. The slowv running device itself is of` any ordinary or ning mixture, which may include heated air admitted at g3 passes through the duct g" to the induction pipe adjacent the throttle as customary. It will also be seen that from the well c there leads a channel /L for the undiluted fuel, and; for the sakeof brevity this channel may be termed an accelerator duct provided with an adjustment screw /L1 to control" the amount offuel" passing todischarge duct h2,- which leads into the inluction pipe at the point designated ha in i ig. 2:

In the embodiment illustrated in Figs. 5 to 7 a horizontal'type ofcarburetor is shown also constructed. to operateon the principlev previously described, andl comprising afloat chamber z' with needlev valve' l and fuel filter assembly The wellv j leadingI from. the` float chamberz' containslrthe calibrated plug jl", which is screwedinto/ an. aperture in the bottom off the Wellin alignment with the air tube jl terminating. above inthe nozzle ja and to which-air is suppliedthrough the port Thenozzlej3 discharges into the Venturi'A tube locatedin the horizontal inn duction` pipe irl containing; the throttlek 7a2, which is operated by the lever- 7c3 and'` is provided with the stop and i adjustment screw 7a4 and 705 respectively. llhecold air inlet to the induction pipe is shownl at Z provided4 with-a. shield Z1 and the usuall Venturi tube plug at Z2. The slow running mixture device m is inclined to the axis of thevmain-nozzle, and the adjustable pipe or duct m1 ol" this device dips at its lowerl end into part of-thewell'y andisheld-in required position` of adjustment` bya lock nut mi. Heated air may be suppliedV to said slow` `running device through the connection m3 and the duct mi for the slow ruiming mixture discharges into the induction pipe adjacenty the throttle as shown at m5 (Fig. 7

The auxiliary fuel'supply through the accelerator ducta passes alongsidefthel slow running mixture, there being'v providedl at the-top afregulating or adjusting4 4screw al for said duct, andv below a plug a2. The discharge n.3 from saidl duct passes into the induction pipe in advancevof the throttle, asshown in F ig; 7

That we claim as our invention and desire to secure by Letters Patentof the United States is:

In a carburetor, the combination, with a constant-level chamber, a mixing. chamber, a throttlevalve therein, a main nozzle dise charging into the mixing chamber, and a secondary deviceV for supplying starting or slow-running mixture also discharging into the mixing chamber; of means for supplying an auxiliary charge of undilutedvliquid fuel into said mixing chamber at small throttle openings, said auxiliary charge being delivappropriate construction andthe slow runered at a point adjacent the point of dis charge of said starting mixture into the Well at a lower level than the auxiliary fuel mixing chamber and also adjacent the closed supply means.

position of the throttle on the atmosphere In witness whereof We have signed this 10 side thereof; and a Well With which the main specification.

nozzle, the starting supply device and the auxiliary fuel supply means communicate, the main nozzle communicating With said ARCHIE DONALD PATERSON. MALCOLM ALLAN GRAY. 

